JP2015178709A - Prestressed concrete pole with strength directionality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pre-stressed concrete pole, which has strength directionality with controlled strength in a direction where less strength suffices, enabling to reduce the costs of the product and the equipment investment.SOLUTION: A pre-stressed concrete pole 1 with strength directionality is configured by arranging a plurality of reinforcement steel bars 9 and 10, which are: placed at designated positions along the circumferential direction in the cross section of a concrete pole main body 2, extending along the longitudinal direction of the concrete pole body 2, in order to introduce compressive forces in the concrete pole main body 2; and positioned so that a first bending strength on a first direction Y at the cross section of the concrete pole main body 2 of the prestressed concrete pole 1 becomes greater than a second bending strength on a second direction X of the prestressed concrete pole 1.

Description

  The present invention has a strength directionality configured such that when an electric wire is installed between a plurality of concrete poles, the bending strength in the direction intersecting the line direction of the electric wire is larger than the bending strength in the line direction of the electric wire. It relates to prestressed concrete poles.

A prestressed concrete pole is a concrete pole that gives a compressive force to a concrete body by pulling a reinforcing bar arranged in the longitudinal axis direction of the concrete pole and releasing the tension state after the surrounding concrete has hardened.
Prestressed concrete poles are superior in bending strength and can be reduced in weight by reducing the diameter of the poles. Therefore, the prestressed concrete poles have the advantage that installation work is easy and transportation costs are kept low.

Looking at the usage of prestressed concrete poles, it is used as a support pillar for transmission and distribution lines and communication lines as shown in FIG.
In FIG. 1, a plurality of prestressed concrete poles 1A to 1D are arranged side by side in a straight line, and the electric wires 3 coming from the left are sequentially connected to the prestressed concrete poles 1A to 1D, and the electric wire arrangement is completed. At this time, since the prestressed concrete poles 1A to 1C except the prestressed concrete pole 1D disposed last are intermediate pillars, if the connection direction of the electric wires 3 is a straight line, the line direction of the electric wires 3 (in FIG. 1) In the direction indicated by the arrow X), the left and right tensions of the electric wires 3 are balanced between the poles, and the load in the line direction hardly acts on the prestressed concrete poles 1A to 1C.

On the other hand, when a strong wind acts in the direction Y crossing the line direction X of the prestressed concrete poles 1A to 1C, for example, the direction orthogonal to the direction (indicated by the arrow Y in FIG. 1), the line direction X The direction of the magnitude of the load that a greater load is applied occurs.
In FIG. 1, the rightmost prestressed concrete pole 1D is connected and fixed to the anchor 5 of the underground G via a branch line 7 diagonally extending downward to the right. The left and right tensions are canceled by this branch line 7.

By the way, the shape of the prestressed concrete pole that has been conventionally made is as shown in the left-end A column prestressed concrete pole (hereinafter referred to as “base pole” as appropriate) 8 in the charts of FIGS. From the cross-section (cross-section at the ground surface position) 8a to the end-portion cross-section (top-end cross-section) 8b, the hollow inner peripheral surface 8c and the outer peripheral surface 8d are both concentric and circular.

  A high-strength steel material (hereinafter referred to as “PC rebar” as appropriate) 9 that is a tension member for introducing a compressive force to the base pole 8 is formed in the circumferential direction of the circular cross section over the entire length of the base pole 8. Are arranged in a plurality of equal distributions (indicated by black circles in the figure), and a high-tensile steel material (hereinafter referred to as “RC reinforcing bar”) 10 as a reinforcing member is interposed between the PC reinforcing bars 9. The base pole 8 is arranged in a plurality of equally distributed circumferential directions (indicated by white circles in the figure), thereby producing a prestressed concrete pole (base pole) 8 having a certain bending strength. I have done it.

The PC rebar 9 is arranged over the entire length of the base pole 8 in order to apply a compressive force to the base pole 8, whereas the RC rebar 10 increases the bending moment of the base pole 8. Since it is the target, it is arranged in a range from the base port 4 of the base pole 8 to a predetermined height. Therefore, the RC rebar 10 exists in the ground section 8a, but the RC rebar 10 does not exist in the end section 8b.

That is, in the conventional base pole 8, as described above, the PC rebar 9 and the RC rebar 10 are arranged at equal positions in the circumferential direction, and therefore, including the line direction X and the direction Y orthogonal thereto, The structure has a constant lateral load strength (bending strength) in the same direction.
Accordingly, the base pole 8 can sufficiently withstand the lateral load in the direction X because the lateral load in the line direction X does not increase as described above with reference to FIG. However, when a larger lateral load than usual is applied in the perpendicular direction Y due to strong winds or the like, the base pole 8 may be destroyed.

In addition, prestressed concrete poles that are long and heavy, once installed, are usually not rebuilt and used for decades as long as there is not much .
If a prestressed concrete pole is viewed from such a viewpoint, it has a relatively large strength in a necessary direction (the orthogonal direction Y) according to the use situation and is relatively small in an unnecessary direction (the line direction X). If a pole having strength, that is, a pole having directionality in the lateral load is prepared, a prestressed concrete pole that is more efficient and economical can be provided.

  In order to solve the above-mentioned problems, a prestressed concrete pole having strength directionality according to claim 1 of the present invention is a predetermined position in the circumferential direction of the cross section of the concrete pole body in order to introduce a compressive force to the concrete pole body. In the prestressed concrete pole in which a plurality of reinforcing bars are arranged so as to extend in the longitudinal direction of the concrete pole body, the bending strength in the first direction acting on the prestressed concrete pole is relative to the cross section of the concrete pole body. The plurality of reinforcing bars are provided so as to be larger than the second bending strength in the second direction acting on the prestressed concrete pole.

Further, the first direction and the second direction can be arranged in a direction orthogonal to each other.
In addition, as a mode in which the first bending strength in the first direction is larger than the second bending strength in the second direction, the first bending strength with respect to a cross section of the concrete pole body It is possible to set the arrangement density of the reinforcing bars arranged in the direction to be larger than the arrangement density of the second reinforcing bars arranged in the second direction.

Further, as another aspect in which the first bending strength in the first direction is larger than the second bending strength in the second direction, It is possible to set the thickness of the first reinforcing bar arranged in the direction 1 to be larger than the thickness of the second reinforcing bar arranged in the second direction.
As still another aspect, the material strength of the first reinforcing bar arranged in the first direction is the material strength of the second reinforcing bar arranged in the second direction with respect to the cross section of the concrete pole body. It is possible to set so that it becomes larger.

In addition, a plurality of reinforcing bars arranged with respect to the concrete pole main body are provided for the purpose of reinforcing the concrete pole main body and a PC reinforcing bar provided over the entire length for the purpose of imparting a compressive force to the concrete pole main body. It can be constituted by two types of reinforcing bars, RC reinforcing bars provided in a range from the main entrance to a predetermined height.
In addition, the cross-sectional shapes of the hollow inner peripheral surface and the outer peripheral surface of the concrete pole body may be concentric with a circular cross section, or the hollow inner peripheral surface may be a circular cross section, and the outer peripheral surface may be the first cross section. You may make it the elliptical cross section which has arrange | positioned the long side so that a direction may be followed.

The prestressed concrete pole having strength directionality according to the present invention has the following effects.
(1) First, with respect to the cross section of the concrete pole body, the first bending strength in the first direction acting on the prestressed concrete pole is the second bending strength in the second direction acting on the prestressed concrete pole. By providing the multiple reinforcing bars, the prestressed concrete pole can be given strength direction, and the cost of capital investment can be reduced by suppressing the strength in unnecessary directions and reducing costs. It becomes possible to reduce. The above effect becomes remarkable when the first direction and the second direction are set in a direction orthogonal to each other.

(2) Further, as an aspect in which the first bending strength in the first direction is made larger than the second bending strength in the second direction, the arrangement density of the first reinforcing bars arranged in the first direction Is set to be larger than the arrangement density of the second reinforcing bars arranged in the second direction, the existing reinforcing bars can be used as they are, and it is relatively easy to change the arrangement density of the reinforcing bars. By the means, it is possible to give the prestressed concrete pole strength direction.
Further, instead of the above aspect, when the thickness of the first reinforcing bar arranged in the first direction is set to be larger than the thickness of the second reinforcing bar arranged in the second direction, Even when the material strength of the first reinforcing bar arranged in the first direction is set to be larger than the material strength of the second reinforcing bar arranged in the second direction, as in the above aspect, the comparison It is possible to give the prestressed concrete pole strength direction by a simple means.

(3) Further, when the plurality of reinforcing bars are composed of two types of PC reinforcing bars and RC reinforcing bars, the strength of the prestressed concrete pole is further improved, and the combination of the arrangement of the PC reinforcing bars and the RC reinforcing bars is changed. It becomes possible to provide various types of prestressed concrete poles suitable for the purpose and application of use.
In addition, when the cross-sectional shapes of the hollow inner peripheral surface and the outer peripheral surface of the concrete pole body are both concentric with a circular cross section, the concrete pole body can be easily molded, and the cross-sectional shape of the outer peripheral surface of the concrete pole body is When the cross section of the hollow inner peripheral surface of the concrete pole main body is a circular cross section, the wall thickness on the long side of the concrete pole main body is Since it becomes thicker than the wall thickness on the short side, the first bending strength in the first direction is made higher than the second bending strength in the second direction in consideration of structural factors of the concrete pole body. It becomes possible to enlarge.

It is the top view (a) and side view (b) which show the usage example of a general prestressed concrete pole. It is explanatory drawing which shows a cross-sectional view and an end-portion cross-sectional view together with a side view showing a general prestressed concrete pole having a circular cross section on both the outer peripheral surface and the hollow inner peripheral surface. An explanation showing the specifications of the two types of directional cylinders according to the first embodiment of the present invention in comparison with a general prestressed concrete pole whose outer peripheral surface and hollow inner peripheral surface are concentric with a circular cross section. FIG. FIG. 4 is an enlarged cross-sectional view of a first pole having a circular cross section according to the first embodiment of the present invention shown in row B in FIG. 3. FIG. 4 is an enlarged cross-sectional view of a second pole having a circular cross section according to the first embodiment of the present invention shown in row C in FIG. 3. FIG. 6 is an explanatory view showing a side view showing a third pole according to the second embodiment of the present invention in which an outer peripheral surface is an elliptical cross section and a hollow inner peripheral surface is a circular cross section, together with a ground cross section and an end cross section. is there. Two types according to the second embodiment of the present invention in which the outer peripheral surface and the hollow inner peripheral surface are both concentric general prestressed concrete poles having a circular cross section and the outer peripheral surface is an elliptical cross section and the hollow inner peripheral surface is a circular cross section. It is explanatory drawing which compares and shows each specification of a directional elliptic cylinder. FIG. 8 is an enlarged cross-sectional view of a third pole having an elliptical cross section according to the second embodiment of the present invention shown in row B in FIG. 7. FIG. 8 is an enlarged cross-sectional view of a fourth pole having an elliptical cross section according to the second embodiment of the present invention shown in row C in FIG. 7.

Hereinafter, the structure and operation mode of the prestressed concrete pole 1 having strength directionality according to the present invention will be specifically described with reference to the illustrated embodiment.
In the following description, the first embodiment and the second embodiment are taken as examples, and the first and second prestressed concrete poles 11 having a circular cross section and the first embodiment are further described. Two types 21 (FIGS. 4 and 5) will be described. Further, the second embodiment will be described by taking up two types of third to fifth prestressed concrete poles 31 and 41 (FIGS. 8 and 9) having an elliptical cross section.

The prestressed concrete poles 11, 21, 31, 41 having the strength direction of the present invention have a plurality of reinforcing bars at predetermined positions in the circumferential direction of the cross section of the concrete pole body 2 in order to introduce a compressive force to the concrete pole body 2. 9 and 10 are concrete poles arranged so as to extend in the longitudinal direction of the concrete pole body 2.
In the prestressed concrete poles 11, 21, 31, 41, the first bending strength in the first direction Y acting on the prestressed concrete pole acts on the prestressed concrete pole with respect to the cross section of the concrete pole body 2. The plurality of reinforcing bars 9 and 10 are provided so as to be larger than the second bending strength in the second direction X.
[First Embodiment]

(1) Prestressed concrete pole 11 with a first circular cross section (hereinafter simply referred to as “first pole 11 with a circular cross section”) (see row B in FIG. 3 and FIG. 4)
The first pole 11 having a circular cross section according to the first embodiment is a concentric concrete pole in which both the outer peripheral surface 19 and the hollow inner peripheral surface 17 of the concrete pole body 2 have a circular cross section. The first direction Y and the second direction X are orthogonal to each other, and when used in a usage pattern as shown in FIG. The second direction in which the bending strength is reduced in the direction Y perpendicular to the line direction X is used for the line direction X of the electric wire 3.

  This first pole 11 is similar to the base pole 8 shown in row A in FIG. 3, and is located outside the entire length L of the first pole 11 from the front port 4 to the end port 6 (FIG. 2) and the ground cross section 13. The diameter D, the outer diameter d of the end section 15, the wall thickness T of the cross section 13 (see row B in FIG. 3, FIG. 4) and the thickness t of the end section 15 are all the same dimensions as the base pole 8. ing. On the other hand, the number of PC reinforcing bars 9 and RC reinforcing bars 10 is small. That is, as shown in FIG. 4, the PC reinforcing bars 9 used in the base pole 8 are reduced in the first pole 11, and the RC reinforcing bars 10 used in the base pole 8 are the same in the first pole 11. The total number of RC reinforcing bars 10a of the same type as the base pole 8 and RC reinforcing bars 10b having different lengths is smaller than the number of base poles 8.

In the first pole 11, the arrangement density of the first reinforcing bars 9 and 10 arranged in the first direction Y with respect to the cross section of the concrete pole body 2 is arranged in the second direction X. It is set to be larger than the arrangement density of the second reinforcing bars 9, 10.
As shown in the B row in FIG. 3, there are deduction regions R and r (see the B row in FIG. 3 and FIG. 4) in which the reinforcing bars 9 and 10 are not arranged at the left and right ends of the ground cross section 13 and the end cross section 15. It has a formed configuration.

The load resistance (cracking test load, which is a reference for bending performance) due to the load at the end 6 of the first pole 11 configured as described above is the bending strength as shown in the B row in FIG. It is 10 kN in the large first direction Y and 7 kN in the second direction X having a small bending strength.
Therefore, the base pole 8 shown in the A row in FIG. 3 has a load resistance due to the load at the end 6 of 10 kN in all directions, and the first pole 11 has 7 kN in the second direction X compared to 7 kN. The load capacity is small. However, since the second direction X is used as the line direction X shown in FIG. 1, a large bending load is not applied in the second direction X, so the load resistance of 7 kN is sufficient.

Further, in the first pole 11, as described above, the number of PC reinforcing bars 9 and RC reinforcing bars 10 is reduced, so that the usage amount of the reinforcing bars 9, 10 of the first pole 11 is shown in the base A in FIG. It becomes smaller than the pole 8 and as a result, the mass of the pole is also reduced.
Therefore, according to the first pole 11 according to the first embodiment of the present invention, it is possible to reduce the cost of the product by the amount of the reinforcing bars 9 and 10 and to reduce the necessary direction (first direction). It is possible to reduce the weight of the first pole 11 while maintaining the load resistance necessary in the direction Y), thereby reducing the product transportation cost and the installation cost.

As an alternative example, in the first pole 11, the arrangement density of the first reinforcing bars 9 and 10 arranged in the first direction Y is the same as the arrangement density of the second reinforcing bars 9 and 10 arranged in the second direction X. The thickness of the first rebars 9 and 10 arranged in the first direction Y is set in the second direction in addition to or in place of this mode. It is also possible to set to be larger than the thickness of the second reinforcing bars 9 and 10 arranged in X.
Further, as an alternative, instead of changing the arrangement density, the material strength of the first reinforcing bars 9 and 10 arranged in the first direction Y with respect to the cross section of the concrete pole body 2 is changed to the second strength. It is also possible to set so as to be larger than the material strength of the second reinforcing bars 9 and 10 arranged in the direction X.

(2) Prestressed concrete pole 21 having a second circular cross section (hereinafter, simply referred to as “second pole 21 (with a circular cross section)”) (see row C in FIG. 3 and FIG. 5)
The second pole 21 related to the prestressed concrete pole 1 according to the first embodiment is similar to the first pole 11 in that both the outer peripheral surface 29 of the concrete pole body 2 and the hollow inner peripheral surface 27 have a circular cross section. It is a concentric concrete pole.
As in the case of the first pole 11, the first direction Y and the second direction X are perpendicular to each other. Further, the overall length, outer diameter, and thickness of the second pole 21 are the same as the base pole 8 shown in the A row in FIG. 3 and the first pole 11 described above in the B row in FIG. 3. .

On the other hand, as shown in row C of FIG. 3 and FIG. 5, the number of PC reinforcing bars 9 and RC reinforcing bars 10 of the second pole 21 is further smaller than that of the first pole 11.
Further, in the second pole 21, similarly to the first pole 11, the arrangement density of the reinforcing bars 9 and 10 on the first direction Y side is larger than the arrangement density of the reinforcing bars 9 and 10 on the second direction X side. The tendency is more conspicuous than that of the first pole 11.

  That is, as shown in row C in FIG. 3 and FIG. 5, in the second pole 21, the deduction regions R and r are larger than the first pole 11 and are arranged in the circumferential direction accordingly. The interval between the rebars 9 and 10 is narrowed. Further, as shown in FIG. 5, the RC rebars 10 are arranged in the ground cross section 23 two by two between the PC rebars 9, and are different from those arranged one by one in the first pole 11. doing.

The load resistance due to the load at the end 6 (FIG. 2) of the second pole 21 configured in this way is the first direction Y where the bending strength is large, as shown in row C in FIG. The same 10 kN as that of the first pole 11 and 5 kN which is smaller than 7 kN of the first pole 11 in the second direction X where the bending strength is small.
Therefore, as in the case of the first pole 11, the use of the second direction X in the line direction X shown in FIG. 1 does not apply a large bending load in the second direction X, so the load resistance of 5 kN is sufficient. It is.

Further, in the second pole 21, the number of PC reinforcing bars 9 and RC reinforcing bars 10 is smaller than that of the first pole 11, so that the approximate mass of the prestressed concrete pole 1 is The mass of the reinforcing bars 9 and 10 is smaller than that of the first pole 11 shown in the B row in FIG.
Therefore, according to the second pole 21 according to the first embodiment of the present invention, it is possible to further reduce the cost of the product as much as the number of the reinforcing bars 9 and 10 is further reduced, and the necessary direction (the first direction) The prestressed concrete pole 1 can be further reduced in weight while maintaining the required load resistance in the direction Y) 1, thereby further reducing the product transportation cost and the installation cost.

  As an alternative example, also in the second pole 21, the arrangement density of the reinforcing bars 9 and 10 on the first direction Y side is set to be larger than the arrangement density of the reinforcing bars 9 and 10 on the second direction X side. However, in addition to this mode or in place of this mode, it is possible to adopt a mode in which the thickness of the reinforcing bars 9, 10 is changed or a mode in which the material strength of the reinforcing bars 9, 10 is changed.

[Second Embodiment]
(1) Prestressed concrete pole 31 having a third elliptical cross section (hereinafter simply referred to as “third pole 31 (with an elliptical cross section)”) (see row B in FIG. 7 and FIG. 8)
The third pole 31 having an elliptical cross section according to the second embodiment has an elliptical cross section in which the cross-sectional shape of the outer peripheral surface 39 of the concrete pole body 2 is a long side in the direction of the first direction Y, and concrete. The hollow inner peripheral surface 37 of the pole body 2 is a concrete pole having a circular cross section. Also, in the second embodiment, as in the first embodiment, the first direction Y and the second direction X are orthogonal to each other, and when used in a usage pattern as shown in FIG. As in the first embodiment, the first direction Y in which the bending strength is increased is set in the direction orthogonal to the line direction X of the electric wire 3, and the second direction X in which the bending strength is reduced is used for the line direction of the electric wire 3. become.

As shown in FIG. 6, the third pole 31 having an elliptical cross section has the same overall length, outer diameter, wall thickness, and the like as the base pole 8 shown in row A of FIG.

Further, the PC reinforcing bars 9 are provided at equal intervals on the elliptical circumference along the outer peripheral surface 39 of the concrete pole body 2 and are smaller than the number of reinforcing bars of the base pole 8 shown in the A row in FIG. .
On the other hand, the RC reinforcing bars 10 are provided with the same number of the same type of base poles 8a as the base poles 8, and further on the long axis side in the cross section 33 shown in FIG. The RC reinforcing bar 10a of the base pole 8 and another type of RC reinforcing bar 10b are increased one by one at positions inside the PC reinforcing bars 9 at both ends.

Further, in the third pole 31, the PC rebar 9 and the RC rebar 10 are arranged on an elliptical circumference along the outer peripheral surface 39 of the concrete pole main body 2, so that the cross section of the concrete pole main body 2 is reduced. Thus, the arrangement density of the first reinforcing bars 9 and 10 arranged in the first direction Y is substantially larger than the arrangement density of the second reinforcing bars 9 and 10 arranged in the second direction X. Yes.
The load resistance due to the load at the end 6 of the third pole 31 configured as described above is 10 kN in the first direction Y where the bending strength is large, as shown in the row B in FIG. 7 kN in the small second direction X.

Accordingly, the third pole 31 has a load resistance of 7 kN in the second direction X as compared with the base pole 8 shown in row A in FIG. 7 having a pair load at the end 6 of 10 kN in all directions. However, since a large bending load is not applied in the second direction X by using the second direction X in the line direction X shown in FIG. 1, the load resistance of 7 kN is sufficient.
Further, in the third pole 31, as described above, the number of PC reinforcing bars 9 is smaller than that of the base pole 8, and the number of RC reinforcing bars 10 is different from that of the base pole 8 by adding another type 10b. Conversely, it is increasing.

As a result, the mass of the reinforcing bars 9 and 10 is smaller in the third pole 31 than in the base pole 8 as shown in rows A and B in FIG. 7, but the outer peripheral surface 39 of the concrete pole body 2 has an elliptical shape. Accordingly, the wall thicknesses T1 and t1 on the long side are increased, and the approximate mass of the prestressed concrete pole 1 is larger than that of the base pole 8.
Therefore, according to the third pole 31 according to the second embodiment of the present invention, the outer peripheral surface 39 of the concrete pole main body 2 has an elliptical shape, and the reinforcing bars 9 and 10 are arranged as described above. Along with this, the third pole 31 is given a strength direction, and a part of the increase in the approximate mass of the third pole 31 is compensated by reducing the mass of the reinforcing bars 9, 10. A pole 31 is obtained.

Further, in the third pole 31, the outer peripheral surface 39 of the concrete pole body 2 is elliptical as an aspect in which the first bending strength in the first direction Y is larger than the second bending strength in the second direction X. The second reinforcing bar having a shape and the arrangement density of the first reinforcing bars 9 and 10 arranged in the first direction Y with respect to the cross section of the concrete pole body 2 is arranged in the second direction X. A configuration in which the arrangement density is set to be larger than 9, 10 is adopted.
Among these, in addition to the aspect of changing the arrangement density, or in place of the aspect of changing the arrangement density, the aspect of changing the thickness of the reinforcing bars 9, 10 and the aspect of changing the material strength of the reinforcing bars 9, 10 are adopted. It is also possible.

(1) Prestressed concrete pole 41 having a fourth elliptical cross section (hereinafter simply referred to as “fourth pole 41 having an elliptical cross section”) (refer to row C in FIG. 7 and FIG. 9).
The fourth pole 41 having an elliptical cross section according to the second embodiment is similar to the third pole 31 in that the cross-sectional shape of the outer peripheral surface 49 of the concrete pole body 2 is elliptical, The circumferential surface 47 is a concrete pole having a circular cross-sectional shape. Then, like the third pole 31, the first direction Y and the second direction X are perpendicular to each other.
Further, the overall length, outer diameter, wall thickness and other dimensions of the fourth pole 41 are all set to be the same as those of the third pole 31 shown in row B in FIG.

The fourth pole 41 has the same number of PC rebars 9 as the third pole 31. However, as shown in the row C and FIG. 9, the outer peripheral surface 49 of the concrete pole main body 2 is provided. It arrange | positions so that it may be unevenly distributed in the edge part by the side of a long axis. Therefore, in the fourth pole 41, there are deduction regions R and r (refer to row C in FIG. 7 and FIG. 4) in which the reinforcing bars 9 and 10 are not disposed on the left and right ends of the ground cross section 43 and the end cross section 45. Is formed.
On the other hand, the number of RC reinforcing bars 10 is smaller in the fourth pole 41 than in the third pole 31.

Further, the RC reinforcing bars 10a of the same type as the base pole 8 are arranged at both ends on the elliptical circumference where the upper and lower PC reinforcing bars 9 are arranged as shown in FIG. Another type of RC reinforcing bar 10b is arranged between the PC reinforcing bars 9 located at both ends of the long side of the concrete pole main body 2 and the PC reinforcing bars 9 and 9 located on the left and right sides thereof as shown in FIG. Yes.
Therefore, in the fourth pole 41, the arrangement density of the reinforcing bars 9, 10 on the first direction Y side is larger than the arrangement density of the reinforcing bars 9, 10 on the second direction X side than the third pole 31. Thus, the prestressed concrete pole 41 is further emphasized in strength directionality.

The load resistance at the end 6 of the fourth pole 41 configured in this way is the same as that of the third pole 31 in the first direction Y where the bending strength is large, as shown in row C in FIG. In the second direction X, which has the same 10 kN and low bending strength, it is 5 kN which is smaller than 7 kN of the third pole 31.
Accordingly, like the third pole 31, the use of the second direction X in the line direction X shown in FIG. 1 does not apply a large bending load in the second direction X, so the load resistance of 5 kN is sufficient. It is.

Further, in the fourth pole 41, the number of RC reinforcing bars 10 is smaller than that of the third pole 31, so that the approximate mass of the prestressed concrete pole 1 and the reinforcing bars 9, 10 are shown in FIG. Is smaller than that of the third pole 31.
Therefore, according to the fourth pole 41 according to the second embodiment of the present invention, it is possible to reduce the cost of the product as much as the number of the RC reinforcing bars 10 is reduced, and the necessary direction (first direction). It is possible to reduce the weight of the prestressed concrete pole 41 and reduce the product transportation cost and the installation cost while maintaining the load resistance necessary for Y).

As an alternative example, in the fourth pole 41 as well, as with the third pole 31, the shape of the outer peripheral surface 49 of the concrete pole body 2 is elliptical, and the arrangement density of the reinforcing bars 9 and 10 on the first direction Y side is the same. Is made larger than the arrangement density of the reinforcing bars 9 and 10 on the second direction X side, thereby making the first bending strength in the first direction Y larger than the second bending strength in the second direction X. Yes.
And in addition to the aspect which changes the arrangement density of the reinforcing bars 9, 10, or in place of the aspect, the aspect in which the thickness of the reinforcing bars 9, 10 is changed or the aspect in which the material strength of the reinforcing bars 9, 10 is changed is adopted. Is also possible.

The above is the basic embodiment of the present invention, but the prestressed concrete pole having the strength directionality of the present invention is not limited to the above-described embodiment, and is a part within the scope of the present invention. It is possible to change or omit the general configuration, or add conventional techniques well known to those skilled in the art.
For example, the numerical values related to the shape and size of the concrete pole main body 2 and the number and arrangement of the reinforcing bars 9 and 10 described in the two types of the first embodiment and the three types of the second embodiment are examples. It can be appropriately changed according to the difference in purpose and application.
[Industrial applicability]

  INDUSTRIAL APPLICABILITY The present invention can be used in the field of manufacturing prestressed concrete poles, construction fields, and the like. In particular, the present invention has applicability when it is desired to reduce the cost by reducing the cost by suppressing the strength in the direction where the prestressed concrete pole is not necessary.

1, 11, 21, 31, 41 Prestressed concrete pole 2 Concrete pole body 3 Electric wire 4 Front port 5 Anchor 6 End port 7 Branch line 8 Base pole 8a, 13, 23, 33, 43 Cross section 8b, 15, 25, 35 , 45 End cross section 8c, 17, 27, 37, 47 Hollow inner peripheral surface 8d, 19, 29, 39, 49 Outer peripheral surface 9 PC rebar 10 RC rebar 11 First directional column 13 Ground cross section 15 End cross section 17 Hollow inner peripheral surface 19 Outer peripheral surface X Line direction (second direction)
Y (first direction) perpendicular to the line direction
D (outside section) outer diameter d (outside section) outer diameter T (outside section) inner thickness t (end section) inner thickness L total length R (outside section) deduction region r (end section) Deduction area D1 (of the cross section) Long side length D2 (of the cross section) Short side length d1 (of the cross section) Long side length d2 (of the cross section) Short Side length

Claims (7)

In order to introduce a compressive force to the concrete pole body (2), a plurality of reinforcing bars (9, 10) are placed at predetermined positions in the circumferential direction of the cross section of the concrete pole body (2), and the length of the concrete pole body (2) is increased. In prestressed concrete poles (11, 21, 31, 41) arranged to extend in the direction,
The bending strength in the first direction (Y) acting on the prestressed concrete pole with respect to the cross section of the concrete pole body (2) is the second bending in the second direction (X) acting on the prestressed concrete pole. A prestressed concrete pole having strength directionality, wherein the plurality of reinforcing bars (9, 10) are provided so as to be larger than strength. In the prestressed concrete pole which has the strength directionality of Claim 1,
A prestressed concrete pole having strength directionality, wherein the first direction (Y) and the second direction (X) are orthogonal to each other. In the prestressed concrete pole having the strength directionality according to claim 1 or 2,
The arrangement density of the first reinforcing bars (9, 10) arranged in the first direction (Y) with respect to the cross section of the concrete pole main body (2) is the first density arranged in the second direction (X). A prestressed concrete pole having strength directionality, which is set so as to be larger than the arrangement density of the two reinforcing bars (9, 10). In the prestressed concrete pole having the strength directionality according to claim 1 or 2,
The thickness of the first reinforcing bars (9, 10) arranged in the first direction (Y) with respect to the cross section of the concrete pole body (2) is the second thickness arranged in the second direction (X). A prestressed concrete pole having a strength directionality characterized by being set to be larger than the thickness of the two reinforcing bars (9, 10). In the prestressed concrete pole having the strength directionality according to claim 1 or 2,
With respect to the cross section of the concrete pole body (2), the material strength of the first reinforcing bars (9, 10) arranged in the first direction (Y) is the second strength (X) arranged in the second direction (X). A prestressed concrete pole having strength directionality, which is set to be larger than the material strength of the reinforcing bars (9, 10). In the prestressed concrete pole having the strength directionality according to any one of claims 1 to 5,
Prestressed concrete having strength directionality characterized in that the cross-sectional shapes of the hollow inner peripheral surface (17, 27) and outer peripheral surface (19, 29) of the concrete pole body (2) are both concentric with a circular cross section. Pole. In the prestressed concrete pole (11, 21, 31, 41) having the strength directionality according to any one of claims 1 to 5,
The cross-sectional shape of the outer peripheral surface (39, 49) of the concrete pole main body (2) is an elliptical cross section in which long sides are arranged along the first direction (Y), and the concrete pole main body (2) The hollow inner peripheral surface (37, 47) of the prestressed concrete pole having a strength directionality characterized by having a circular cross section.

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